RU2443526C1 - Method of jointing heterogeneous materials - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of heterogeneous materials and may be used in ship and aircraft building, chemical machine building, etc. Proposed method comprises making holes in part from lower-infusibility material compared with that of another part and acting on the former by rotary cylindrical tool. Metric or conical thread is made in said holes. Tool is revolved in direction mating that of thread turns.

EFFECT: higher adhesion in, for example, steel-aluminium joint.

6 cl, 4 dwg, 1 tbl

Description

The invention relates to the field of engineering and can be used to obtain compounds of dissimilar materials in shipbuilding, aviation, chemical engineering and other industries.

The closest in technical essence and the achieved result is the STIR-LOCK technology for producing steel-aluminum compounds, which we adopted as a prototype (see Friction stir technology - recent developments in process variants and applications [Electronic resource] / Staines DG, Thomas WM, Kallee SW and Oakley PJ - United Kingdom: TWI Ltd, 2006. - Access mode http://www.twi.co.uk/content/spwmtoct2006.html. - Heading from the screen.). The compound is prepared as follows. Initially, holes are made in a more refractory plate. The plate is fixed, and on top of it a plate of less refractory and more ductile metal (aluminum alloy) is laid and fixed. Then a rotating tool in the form of a cylinder mounted at an angle of 1-5 ° relative to the vertical axis is lowered to the assembled parts and embedded in a more plastic of them to a depth of 0.2-0.5 mm. In this case, heating and plasticization of the upper part occurs, and the tool moves along the holes with the angle forward. In this case, plasticized metal moving above the hole fills the holes. Thus, a mechanical connection is formed with a rivet from the body of a more fusible metal.

A disadvantage of the known technology is that lap joints loaded with axial force work not only for shear, but also for tearing, which can lead to premature failure.

The technical result of the invention is to increase the strength of compounds of dissimilar materials, for example, in steel-aluminum compounds.

The technical result is achieved in that in a method for producing lap joint of parts from dissimilar materials, which includes making parts of a more refractory material than other parts, holes, placing parts of a more fusible material on it, deepening a rotating cylindrical tool installed at an angle, into a part from a more fusible material and moving it along a part from a more fusible material along the holes in a part from a more refractory material, the difference is It is Busy that operate in the holes or conical metric thread and the rotation of the tool is performed in a direction similar to the direction of the threads.

When exposed to a part from a more fusible material by a rotating cylindrical tool, a rivet is formed from a more fusible material due to the pressure and heating created by the tool. Due to the presence of thread in the holes, as well as the coincidence of the direction of rotation of the tool with the direction of the threads, the rivet material is screwed into the holes and fills the grooves of the thread, forming an integral threaded connection.

For example, steel can be used as a refractory material, and aluminum or its alloys can be used as a low-melting material.

As a tool, a cylindrical tool used for friction stir welding can be used. The tool can be installed at an angle of 1-5 ° with respect to the vertical axis and is buried by 0.2-0.5 mm in a low-melting material.

When implementing the method, it is possible to carry out additional heating of a part from a more refractory material with a heating device to a temperature that causes plasticization of the part from a more fusible material.

The inventive method is illustrated by drawings.

Figure 1 presents the connection production scheme, where 1 is a cylindrical tool with a flat end, 2 is a part of a more refractory material containing threaded holes, 3 is a part of a more fusible material.

On figa presents the appearance of the obtained compounds according to the proposed method from the side of the impact of the tool (front side).

On figb presents the appearance of the obtained compound according to the proposed method from the reverse side, where 4 is a rivet.

Figure 3 presents the appearance of the samples after destruction made by the proposed method, where 2 is a part of a more refractory material, 3 is a part of a more fusible material, 5 is the place of destruction.

Figure 4 presents the appearance of the samples after destruction, made according to the prototype, where 2 is a part of a more refractory material, 3 is a part of a more fusible material, 5 is a place of destruction.

The connection is as follows.

On a part 2 made of a refractory material, for example, steel, holes are made on the inner surface of which a metric or tapered thread is made. Part 2 is laid on the table of the milling machine, part 3 is mounted on top, for example, of aluminum alloy. These parts are firmly fixed on the table. After that, a rotating tool 1 is brought to them, buried in part 3 and moved along it along the holes. Due to the friction of the end face of the cylindrical tool 1 about the part 3, the connected parts are heated. And due to the tilt of the tool 1 and its movement, pressure arises. In this case, the more plastic material of part 3 fills the threaded holes in part 2, forming an integral threaded connection.

The following is an example implementation of the method.

In laboratory conditions, plate joints were made 155 mm long, 40 mm wide with a steel plate thickness of 2 mm and a plate made of aluminum alloy AD31T 4 mm thick by the proposed method. A milling machine was used as a tool drive.

Connection Receive Mode:

The diameter of the cylindrical tool with a flat contact surface D is 25 mm;

Tool rotation speed - 710 rpm;

Tool material - 08X18H10T;

The angle of the instrument relative to the vertical axis a - 2 degrees;

The depth of the tool h - 0.2 mm;

Speed of longitudinal movement of the tool - 40 mm / min;

Hole configuration - cylindrical holes with a diameter of 8 mm without thread and with metric thread M8.

The obtained compounds were tested on a tensile testing machine UMM10. The test results are shown in table 1 and figure 3.

For comparison, table 1 and figure 4 show the test results of similar joints with holes of different configurations and without thread.

Table 1 Sample Type The maximum force before the destruction of the connection, kg Lap joint with three rivets formed from the body of a more fusible material (AD31T) of a cylindrical hole without thread - prototype 400 Lap joint with three rivets formed from the body a more fusible material (AD31T) of a cylindrical hole with a metric thread 750

As can be seen from the table, the rivet connection (prototype) was destroyed at 400 kg (figure 4). In the case of the compound obtained by the proposed method, the destruction occurred at 750 kg (figure 3). That is, the strength of the connection obtained by the proposed method is 1.8-2.0 times higher than when connecting without thread.

The test results also showed that when using additional heating to a temperature that causes plasticization of a more fusible material, the yield strength of materials decreases, which leads to a better flow of a more fusible material and a better filling of holes in a more refractory material, which is especially useful when connecting parts of a larger thickness.

Thus, the use of the proposed method of joining dissimilar materials allows you to get a connection with high strength characteristics.

Claims (6)

1. A method of obtaining a connection of parts from dissimilar materials, comprising making holes in a part of a more refractory material than the other part material, placing parts of a more fusible material on it, deepening a rotating cylindrical tool installed at an angle into a part of a more fusible material, and moving it over a part of a more fusible material along the holes in a part of a more refractory material, characterized in that a metric or conic is cut in the holes thread, and the rotation of the tool is carried out in the direction coinciding with the direction of the threads. 2. The method according to claim 1, characterized in that they conduct additional heating of the more refractory material with a heating device to a temperature causing plasticization of the more fusible material. 3. The method according to claim 1, characterized in that steel is used as a refractory material. 4. The method according to claim 1, characterized in that aluminum or its alloys are used as the fusible material. 5. The method according to claim 1, characterized in that the tool used is a cylindrical tool used for friction welding with stirring. 6. The method according to claim 1, characterized in that the tool is installed at an angle of (1-5) ° with respect to the vertical axis and is buried by 0.2-0.5 mm in a more fusible material.

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